U.S. patent application number 11/518276 was filed with the patent office on 2007-06-07 for advanced hypersonic magnetic jet/electric turbine engine (ahmjet).
Invention is credited to Richard H. Lugg.
Application Number | 20070126292 11/518276 |
Document ID | / |
Family ID | 37889302 |
Filed Date | 2007-06-07 |
United States Patent
Application |
20070126292 |
Kind Code |
A1 |
Lugg; Richard H. |
June 7, 2007 |
Advanced hypersonic magnetic jet/electric turbine engine
(AHMJET)
Abstract
With turbine segments controlled electrically in a shaftless
design, the turbine of the present invention creates high
propulsion efficiencies over a broader range of operating
conditions through the integration of gas turbine, electric and
magnetic power systems, advanced materials and alternative
petroleum-based combustion cycles.
Inventors: |
Lugg; Richard H.; (Falmouth,
ME) |
Correspondence
Address: |
BURNS & LEVINSON LLP
1700 K STREET, NW
SUITE 720
WASHINGTON
DC
20006
US
|
Family ID: |
37889302 |
Appl. No.: |
11/518276 |
Filed: |
September 11, 2006 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60715783 |
Sep 9, 2005 |
|
|
|
Current U.S.
Class: |
310/11 |
Current CPC
Class: |
F01D 5/03 20130101; F02K
5/00 20130101; F05D 2240/515 20130101; Y02T 50/60 20130101; F02K
7/10 20130101; F02K 3/08 20130101; F05D 2220/34 20130101; F03H
1/0081 20130101; F02K 3/00 20130101; F03H 99/00 20130101 |
Class at
Publication: |
310/011 |
International
Class: |
G21D 7/02 20060101
G21D007/02 |
Claims
1. A system for operating a jet turbine engine, said system
comprising: an exoskeleton turbine having dual phase lock
attributes, wherein said exoskeleton turbine is shaftless; an
electric controller for controlling said exoskeleton turbine; a
main compressor; a diffuser; and a plurality of turbine components,
wherein said compressor, said diffuser and said plurality of
turbine components are in dynamic compression.
2. The system of claim 1, wherein said plurality of turbine
components is composed of ceramic matrix.
3. The system of claim 2, wherein said plurality of turbine
components is composed of hafnium carbide fiber reinforced ceramic
matrix.
4. The system of claim 2, wherein said plurality of turbine
components include stators, compressor vanes, turbine blades,
diffuser, combustor casing, annular combustors, shroud segments,
and turbine discs.
5. The system of claim 5, wherein said plurality of turbine
components is composed of continuous ceramic reinforcement
fiber.
6. A system for creating magneto hydrodynamic drive, said system
comprising: a supersonic turbine jet flow; an alkaline substance
stored within a jet turbine engine; and a gas stream having a
substantial air speed; wherein said supersonic turbine jet flow is
ionized with said alkaline substance and produces a power from said
gas stream to create said magneto hydrodynamic drive.
7. The system of claim 4, wherein the air speed of the gas stream
is supersonic.
8. The system of claim 4, wherein the air speed of the gas stream
is hypersonic.
9. A system for providing power for magnetic levitation, said
system comprising: a jet engine turbine having a rear; an outer
casing of said jet engine turbine, said outer casing capable of
bearing air; an airframe in which said outer casing is embedded; a
turbine component having a trunion casing and also having a
magnetic air bearing, wherein power is produced from said rear of
said jet engine turbine for magnetic levitation of said outer
casing; a magnet induction coil ring motor adjacent to said
magnetic air bearing, and wherein power is further provided to
electrically drive the turbine component with said magnetic
induction coil ring motor.
10. The system of claim 7, wherein said turbine component is a
compressor.
11. The system of claim 7, wherein said turbine component is a
diffuser.
12. The system of claim 7, wherein said turbine component is a
turbine.
13. The system of claim 7, wherein said turbine component is
composed of ceramic matrix.
14. The system of claim 13, wherein said turbine component is
composed of hafnium carbide fiber reinforced ceramic matrix.
15. The system of claim 14, wherein said turbine component is
composed of continuous ceramic reinforcement fiber.
16. A system for operating a jet turbine engine, said system
comprising: an exoskeleton turbine having dual phase lock
attributes, wherein said exoskeleton turbine is shaftless; an
electric controller for controlling said exoskeleton turbine; a
main compressor; a diffuser; an annular combustor; a turbine
generator; and a gas-plasma dynamic generator, wherein said
compressor, said diffuser, said combustor, said turbine generator,
and said gas-plasma dynamic generator are in dynamic
compression.
17. The system of claim 16, wherein the main compressor is a
multi-stage rotor.
18. The system of claim 16, wherein the diffuser is a multi-stage
stator.
19. The system of claim 16, wherein the annular combustor is a
donut-ring diffuser.
20. The system of claim 16, wherein the turbine generator is
multi-stage.
21. A method of operating a magneto hydrodynamic drive generator in
the turbine stage, said method comprising: providing electric power
from a magnetic ring motor; providing said electronic power to a
plurality of ring motors in the compressor stage; providing said
electric power to a magnetic air bearing system; and starting the
magneto hydrodynamic drive generator.
22. A system for closing compressor blades during hypersonic
flight, said system comprising: an engine inlet a compressor stage
having an aperture in the center of the compressor stage through
which intake air is channeled; wherein said engine inlet closes
said compressor blades and further wherein said aperture in the
compressor stage causes drag from said compressor blades to be
avoided.
23. A system for closing power turbine blades, said system
comprising: a combustor; a high velocity air stream; a power
turbine a plurality of blades of said power turbine; and a petal
cone aft of said combustor for closing said plurality of blades,
wherein combustion is implemented in said high velocity air stream,
and further wherein said combustion enters said combustor through a
space in said jet engine turbine.
24. The system of claim 23, wherein the high velocity air stream is
at least supersonic.
25. A system for generating electrical current, said system
comprising: a magneto hydrodynamic drive generator; an alkaline
substance seed; a high-mach turbine efflux gas stream having a
positive charge and ionized by said alkaline substance seed; a
plurality of magnetic ring plates having a negative charge; and an
exoskeleton turbine casing in which said plurality of magnetic ring
plates are embedded, wherein said high-mach turbine efflux gas
stream crosses perpendicular to said magnetic ring plates to
generate electrical current.
26. The system of claim 25, wherein said magneto hydrodynamic drive
generator produces approximately 10 to 12 megawatts of electrical
power.
27. The system of claim 25, wherein the alkaline substance seed is
one of cesium, selenium, or potassium.
28. A method of manufacturing turbine components with continuous
ceramic fiber, said method comprising: untwisting a plurality of
fibers; alternatively breaking said plurality of fibers once to
form at least one right angle; and weaving said plurality of fibers
into a net shape perform.
29. The method of claim 28, wherein said fibers are composed of
hafnium carbide.
30. The method of claim 28, wherein said fibers are composed of
silicone carbine reinforcement fiber.
31. A method of manufacturing ceramic fiber reinforced composite
component tools, said method comprising: untwisting a plurality of
fibers; alternatively breaking said plurality of fibers once to
form at least one right angle; weaving said plurality of fibers
into a net shape perform; laying said net shape perform into a tool
containing coated mold release; closing said tool; injecting a glue
into a plurality of ports of said tool; and curing said tool under
pressure and temperature for a predetermined time.
32. The method of claim 31, wherein said tool is composed of highly
alloyed aluminum.
33. The method of claim 31, wherein said glue is composed of a
silica carbide matrix.
34. The method of claim 31, wherein the tool is cured to
approximately 7 to 8 atmospheres.
35. The method claim 31, wherein the tool is cured to at least 1200
degrees Fahrenheit.
36. The method of claim 31, wherein the tool is cured for a period
inside the range of 48 to 72 hours.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn. 119
from provisional application Ser. No. 60/715,783, filed Sep. 9,
2005, and entitled "Magneto Hydrodynamic Maglev Hybrid Electric
Turbine".
FIELD OF THE INVENTION
[0002] The invention is related to the operation of a jet/electric
turbine propulsion system at ideal compression, combustion and burn
efficiencies, and at higher temperatures, throughout a broader
range of operation, from low subsonic to high hypersonic flight
speeds.
BACKGROUND
[0003] Gas turbine engines, and the devices that are powered by gas
turbine engines, are limited in overall design and performance by
mechanical, material, and thermodynamic laws. They are further
constricted by the design limitations of the three elements that
make up the baseline design of gas turbine engines: the compressor,
the combustor and the turbine. In turbines for aircraft, these
three engine sections are contained inside of the outer turbine
casing and are centered on a load bearing drive shaft that connects
the turbine (on the rearward portion of the drive shaft) with the
compressor (on the forward portion of the drive shaft). Typically
the drive shaft is a twin or triple spool design, consisting of two
or three concentric rotating shafts nested one inside the other.
The different spools allow the turbine assembly and the compressor
assembly, each of which is connected to one of the spools of the
drive shaft, to rotate at different speeds.
[0004] The turbine is optimized to run at one particular speed for
combustion and thrust processes, and the compressor is optimized at
a different speed to more efficiently compress incoming air at the
inlet face and raise the air pressure to a significant point to
where there is a pressure ratio differential, significant enough to
provide combustion. Highly compressed air at ratios of 30:1 to 40:1
ignites when mixed with atomized fuel in the combustor. The
difference in speeds of the spools is typically accomplished by
reduction gears to accommodate the required speeds for combustion
and propulsion operation.
[0005] The compressor assembly consists of numerous compressor
stages, each of which is made up of a rotor and a diffuser, the
number of stages dependent upon the total pressure ratio increase
required to achieve combustion and produce the desired thrust. The
rotor is a series of rotating airfoil blades, or fans (attached to
the shaft), which converge the air, i.e., compressing the volume of
air and increasing it's velocity, on the intake side of the blade,
by passing it into a smaller volumes (convergent channels between
airfoil rotor blades) in each the rotor chamber. Adjacent to each
rotor is a diffuser (or stator). The diffuser is a fixed,
non-rotating disc of airfoil stators whose sole purpose is to
reduce the air velocity from the rotor and increase the pressure.
The diffuser slows the air down by passing it through divergent
(expanding) channels between the airfoil stators, thus recovering
the pressure. Upon entering the diffuser the air passes from a
narrow opening on the intake side of the diffuser into a gradually
enlarging chamber (diffuser) that slows the velocity and raises the
pressure of the air. Each compressor stage is made up of a
compressor rotor and a diffuser (stator) disc. There are as many
stages of the compressor as are required to get the air to the
required air temperature and compression ratio (in high performance
aircraft turbines usually in between 12:1 to 30:1 dependent on
combustor design, flight and speed envelope and turbine thrust
requirements prior to entering the combustor.
[0006] In the combustor, the high pressure, high temperature,
expanding air mixes in a swirl of hot vaporized fuel and ignites to
form a controllable flame front. The flame front expands as it
combusts, rotating and driving turbine blades as the flame front
exits the engine. The turbine assembly consists of several sets of
rotating turbine blades connected to the drive shaft and angled so
that the thrust of the flame front causes the blades to rotate. The
turbine blades, being connected to the drive shaft, cause the drive
shaft to rotate and thus the compressor blades to rotate,
consequently more air is compressed and the cycle starts all over
again.
[0007] The Advanced Hypersonic Magnetic Jet-Electric Turbine
(AHMJET) technology of the present invention integrates turbine,
electric generation, magnetic power systems and propulsion,
advanced materials technology, and alternative petroleum-based
combustion cycles, to achieve a significant improvement in
horsepower, combustion efficiency, electric power generation,
flight envelope integration, and affordability over traditional gas
turbine technology.
SUMMARY
[0008] One aspect of the invention pertains to a system for
operating a jet turbine engine, said system comprising an
exoskeleton turbine having dual phase lock attributes, wherein said
exoskeleton turbine is shaftless; an electric controller for
controlling said exoskeleton turbine; a main compressor; a
diffuser; and a plurality of turbine components, wherein said
compressor, said diffuser and said plurality of turbine components
are in dynamic compression.
[0009] A second aspect of the invention relates to a system for
creating magneto hydrodynamic drive, said system comprising a
supersonic turbine jet flow; an alkaline substance stored within a
jet turbine engine; and a gas stream having a substantial air
speed; wherein said supersonic turbine jet flow is ionized with
said alkaline substance and produces a power from said gas stream
to create said magneto hydrodynamic drive.
[0010] A third aspect of the invention relates to a system for
providing power for magnetic levitation, said system comprising a
jet engine turbine having a rear; an outer casing of said jet
engine turbine, said outer casing capable of bearing air; an
airframe in which said outer casing is embedded; a turbine
component having a trunion casing and also having a magnetic air
bearing, wherein power is produced from said rear of said jet
engine turbine for magnetic levitation of said outer casing; and a
magnet induction coil ring motor adjacent to said magnetic air
bearing, and wherein power is further provided to electrically
drive the turbine component with said magnetic induction coil ring
motor.
[0011] A fourth aspect of the invention discloses a system for
operating a jet turbine engine, said system comprising an
exoskeleton turbine having dual phase lock attributes, wherein said
exoskeleton turbine is shaftless; an electric controller for
controlling said exoskeleton turbine; a main compressor; a
diffuser; an annular combustor; a turbine generator; and a
gas-plasma dynamic generator, wherein said compressor, said
diffuser, said combustor, said turbine generator, and said
gas-plasma dynamic generator are in dynamic compression.
[0012] A fifth aspect of the invention pertains to a method of
operating a magneto hydrodynamic drive generator in the turbine
stage, said method comprising providing electric power from a
magnetic ring motor; providing said electronic power to a plurality
of ring motors in the compressor stage; providing said electric
power to a magnetic air bearing system; and starting the magneto
hydrodynamic drive generator.
[0013] A sixth aspect of the invention relates to a system for
closing compressor blades during hypersonic flight, said system
comprising an engine inlet; and a compressor stage having an
aperture in the center of the compressor stage through which intake
air is channeled; wherein said engine inlet closes said compressor
blades and further wherein said aperture in the compressor stage
causes drag from said compressor blades to be avoided.
[0014] A seventh aspect of the invention pertains to a system for
closing power turbine blades, said system comprising a combustor; a
high velocity air stream; a power turbine; a plurality of blades of
said power turbine; and a petal cone aft of said combustor for
closing said plurality of blades, wherein combustion is implemented
in said high velocity air stream, and further wherein said
combustion enters said combustor through a space in said jet engine
turbine.
[0015] An eighth aspect of the invention discloses a system for
generating electrical current, said system comprising a magneto
hydrodynamic drive generator; an alkaline substance seed; a
high-mach turbine efflux gas stream having a positive charge and
ionized by said alkaline substance seed; a plurality of magnetic
ring plates having a negative charge; and an exoskeleton turbine
casing in which said plurality of magnetic ring plates are
embedded, wherein said high-mach turbine efflux gas stream crosses
perpendicular to said magnetic ring plates to generate electrical
current.
[0016] A ninth aspect of the invention discloses a method of
manufacturing turbine components with continuous ceramic fiber,
said method comprising untwisting a plurality of fibers;
alternatively breaking said plurality of fibers once to form at
least one right angle; and weaving said plurality of fibers into a
net shape perform.
[0017] A tenth aspect of the invention pertains to a method of
manufacturing ceramic fiber reinforced composite component tools,
said method comprising untwisting a plurality of fibers;
alternatively breaking said plurality of fibers once to form at
least one right angle; weaving said plurality of fibers into a net
shape perform; laying said net shape perform into a tool containing
coated mold release; closing said tool; injecting a glue into a
plurality of ports of said tool; and curing said tool under
pressure and temperature for a predetermined time.
[0018] It is an object of the invention to provide a shaftless,
electrically controlled, in-and-out phase lock exoskeleton turbine,
with the main compressor, diffuser and turbine components in
dynamic compression.
[0019] Another object of the invention is to provide a magneto
hydrodynamic drive ("MHD") that is created by ionizing the
supersonic turbojet flow with a stored alkaline substance to
produce megawatts of electrical power from the Mach 2.8-5.8+gas
stream.
[0020] It is another object of the invention to provide power from
the rear of the turbine for magnetic levitation of the air bearing
outer casing, embedded into the airframe at the segmented
shaft-less compressor (rotor), diffuser (stator) and turbine
stages, and for all other electric needs of aircraft, and directed
energy payloads. It simultaneously provides power to drive the
compressor electrically with the magnet induction coil ring motors
that sit adjacent to the magnetic air bearing in each trunion
casing of the compressor, diffuser and turbine.
[0021] Another object of the invention is to provide ceramic matrix
components (stators, compressor vanes, turbine blades, diffuser,
combustor casing, annular combustors, shroud segments, and turbine
discs) for light weight and high temperature operation.
[0022] Still another object of the invention is to provide a
shaftless, electrically controlled, in-and-out phase lock
exoskeleton turbine, with a multi-stage compressor/diffuser
(rotor/stator), a donut-ring diffuser annular combustor, a
multi-stage turbine generator, and a gas-plasma dynamic generator
(magneto hydrodynamic drive generator ("MHD"), with all rotating
turbine components being maintained in dynamic compression by a
magnetic levitation ("maglev") system.
[0023] Another object of the invention is to provide a multi-stage
magnetic ring motor/generator in the turbine stage that provides
electric power to the compressor stage ring motors and the magnetic
air bearing system before the MHD generator comes on-line providing
seamless electromagnetic power generation and propulsion between
supersonic and hypersonic operation.
[0024] It is also an object of the invention to provide a petal
cone engine inlet/diffuser that closes off the compressor blades
during hypersonic flight, leaving the shaft hole in the center of
the compressor stage as an aperture through which intake air is
channeled (the aperture acts as a hypersonic compression ram), and
drag from the compressor blades is avoided).
[0025] Another object of the invention is to provide a second petal
cone aft of the combustor that closes off the blades of the power
turbine (with both the inlet and turbine cones closed, the AHMJET
operates as a pure hypersonic scramjet, implementing combustion in
the high velocity air stream (Mach 2.8 and higher) that enters the
combustor through the space in the turbine that would normally be
occupied by a turbine shaft).
[0026] Another object of the invention is to provide an MHD
generator that generates electrical current from a positively
charged high-mach turbine efflux gas stream (ionized by an alkaline
substance seed such as cesium, selenium, potassium) crossing
perpendicular to negatively charged magnetic ring plates embedded
in the exoskeleton turbine casing (the generator produces
continuous levels of electrical power in the range of 10.0 to 12.0
MW, which can be used to power energy weapons, sensors or other
payloads, and all vehicle electrical subsystems).
[0027] It is also an object of the invention to provide ceramic
matrix components (stators, compressor vanes, turbine blades,
diffuser, combustor casing, annular combustors, shroud segments,
and turbine discs) for light weight and high temperature
operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 provides a detailed depiction of the jet-electric
turbine of the present invention.
[0029] FIG. 2 illustrates a Cross Section of the AHMJET technology
of the present invention.
[0030] FIG. 3A illustrates a three dimensional View of the Advanced
Hypersonic Magnetic Jet Electric Turbine (AHMJET) of the present
invention
[0031] FIG. 3B illustrates an enlargement of the magnetic
levitation gap depicted in 3D.
[0032] FIG. 3C illustrates a view of the proximal end of the
jet-electric turbine of the present invention.
[0033] FIG. 3D provides an additional view of the components of the
jet-electric turbine.
[0034] FIG. 4A depicts a three-dimensional view of compressor/rotor
of a stator in the AHMJET Turbine
[0035] FIG. 4B depicts an enlargement of a portion of the cross
section of the rotor and stator in the compression stage.
[0036] FIG. 4C depicts a frontal view of the intake and rotor.
[0037] FIG. 4D depicts cross section of a rotor/stator in the
compression stage
[0038] FIG. 5--Depiction of the starting stage of the combustion
phase of the jet-electric turbine
[0039] FIG. 6A--Depiction of the idle-up stage of the hypersonic
MHD drive
[0040] FIG. 6B--Depiction of the by-pass air gate during the
idle-up stage
[0041] FIG. 7A--Depiction of the subsonic stage of the hypersonic
MHD drive
[0042] FIG. 7B--Depiction of the proximal end of the hypersonic MHD
drive during the subsonic stage
[0043] FIG. 8A--Depiction of the transonic stage of the hypersonic
MHD drive
[0044] FIG. 8A-1--Depiction of the distal end of the hypersonic MHD
drive during the transonic stage
[0045] FIG. 8B--Depiction of the combustor turbine gate of the
transonic stage
[0046] FIG. 9A--Illustration of the supersonic stage of the
hypersonic MHD drive
[0047] FIG. 9B--Depiction of the proximal end of the hypersonic MHD
drive during the supersonic stage
[0048] FIG. 10A--Illustration of the transhypersonic stage of the
hypersonic MHD drive
[0049] FIG. 10B--Depiction of the distal end of the hypersonic MHD
drive during the transhypersonic stage
[0050] FIG. 11--Illustration of the hypersonic stage of the
hypersonic MHD drive
[0051] FIG. 12--Detailed illustration of the hypersonic stage of
the hypersonic MHD drive with enlargements of the rotor and ring
motor armature
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0052] For the purposes of promoting an understanding of the
principles of the invention, reference will now be made to the
embodiment illustrated in the drawings and specific language will
be used to describe the same. It will nevertheless be understood
that no limitation of the scope of the invention is thereby
intended, such alterations and further modifications in the
illustrated apparatus, and such further applications of the
principles of the invention as illustrated therein being
contemplated as would normally occur to one skilled in the art to
which the invention relates.
[0053] The alternative aerospace propulsion technology of the
present invention integrated into this integrated aerospace
propulsion produces sequentially across the flight envelop
subsonic, transonic, supersonic and hypersonic velocity
capabilities, from flight speeds as low as 100 KTAS flight
capability for loiter, maximum thrust of 20,000-25,000 lb. and
produce more than 10 MW of power from a 1000 lb. turbo machine. The
technology consists of staged engine segments of compressor,
combustor, turbine and plasma gas magneto hydrodynamic (MHD) drive
generator, controlled electrically and magnetically in a shaftless
exoskeleton architecture. This advanced hypersonic magnetic
jet-electric turbine (AHMJET) achieves increases in thrust to
weight ratio, specific thrust, mass flow-through capability, stage
pressure ratio efficiency and increase, low thrust specific fuel
consumption, and high electric power generation (12.0 MW) across a
very broad flight envelope (low subsonic to high hypersonic) over a
wide range of atmospheric conditions.
[0054] In addition, the AHMJET is a true hybrid as it operates as
both a propulsion machine and an electric generation machine
simultaneously. Its propulsion system operates as a low-bypass
turbofan in subsonic mode, as a turbojet in supersonic mode and as
a scramjet in hypersonic mode. The AHMJET is able to transition
from one mode to another by altering its engine segment systems
electrically and magnetically across the flight envelope. The
AHMJET, by opening up the design continuum of future manned and
unmanned air vehicles, has the potential of replacing existing gas
turbine technologies.
[0055] The key components of the turbine propulsion system are
disengaged or engaged electrically so that combustion cycles,
cooling, thrust, and electric generation can be arranged and
optimized for high thermodynamic and combustion efficiencies across
the entire flight envelope, regardless of altitude, air density,
temperature and other operating constraints.
[0056] FIG. 1 depicts a preferred embodiment of the turbine
propulsion system 10 of the present invention. The system 10
contains controllers 100, M1 through M10) which are connected to a
computer 101, a power bus 102 and an inverter 103. Each controller
100 is directly connected to a ring motor 106 on the jet-electric
turbine. The power bus 102 is associated with a plurality of ring
motor generator coils 110. The inverter 103 is coupled to magneto
hydrodynamic drive seeding ports 104. Situated next to the seeding
ports is the velocity gate exhaust mechanism 105.
[0057] The proximal portion of the system 10 contains an intake 120
having a low bypass air inlet 107 and a petal cone aft 108. The
petal cone aft 108 is directly attached to the hypersonic
compression ram 111, to which a series of rotors 113 are coupled.
Below the rotors are the rotor trunions 114 and stators 115. These
are, in turn, coupled to controllers 100, which are linked to
computer 101 and inverter 103 in the manner previously described
herein. The hypersonic compression ram abuts the combustor 109.
Therein, a second petal cone 119 is situated. Also abutting the
combustor 109 is hypersonic exhaust 112.
[0058] Ring motor turbine trunion magnets 118 are coupled as
depicted. Adjacent are cables which stem from inverter 103 to
magneto hydrodynamic seeking ports 104. Electromagnetic plates 117
are attached to the gate mechanism 105.
[0059] Compared to current turbine propulsion systems, the AHMJET
system is designed to operate at ideal compression, combustion and
burn efficiencies, and at higher temperatures, throughout a broader
range of operation, from low subsonic (Mach 0.3) to high hypersonic
(Mach 5.8+) flight speeds. This is due to the magnetic,
thermodynamic, mechanical and electric technologies that enables
that which is set forth below.
[0060] Pressure Ratio compressibility is matched to multiple design
point operating conditions. Because the compressor of the invention
has one or more rotor stages (compressor and diffuser), each being
driven by one or more electric motors, the compressor rotor stages
may be designed and tuned more precisely to the compression ratio
to be attained within the turbine design operating characteristics,
thrust requirements and flight envelope. Therefore this allows for
optimal aerodynamic design and efficiencies of the rotor stages in
the compressor and subsequently the possibility of fewer stages
needed (hence potential significant weight savings) to achieve the
required compression ratios for operation of the turbine. Because
each compressor rotor may be driven independently and at different
speeds, the engine may be used more efficiently at different stages
of the flight envelope.
[0061] FIG. 2 illustrates a cross section of the AHMJET technology
of the present invention. The intake 120 contains the hypersonic
compression ram 111. The rotors 113 are depicted on this proximal
side of the jet-electric turbine. At the center of the turbine,
combustor 109 is positioned. The hypersonic compression ram 112 is
shown along with velocity gate exhaust mechanism 105.
[0062] The use of an electric ring motor 106 to drive a compressor
rotor 113 enables the compressor rotor 113 to generate higher
torque than a shaft driven compressor rotor 113 (because the
compressor fan rotors are being driven from the tip of the blade at
the circumference of the rotor 113 rather than from the root or
hub, (and the leverage moments required to overcome mechanical
loading are in an order of magnitude less) and enables the
compressor stage to move larger amounts of the required mass air
flow (due to the disc loading being raised and RPM and mass air
flow optimized) and to feed the combustor 109 and turbine than in
the case of a shaft driven compressor rotor.
[0063] A three-dimensional image of the jet-electric turbine is
shown in FIG. 3A. FIG. 3B shows the detailed magnetic levitation
gap 305 in enlarged section 301. The frontal view of the proximal
portion of the turbine can be seen in FIG. 3C, wherein petal cone
aft 109 protrudes from the intake section. Section A-A of FIG. 3C
is illustrated in detail in FIG. 3D. Section B or 301 containing
the magnetic levitation gap is illustrated herein. Armatures 304
are viewable on the outermost portion of the compressor blades 306
and turbine blades 300. The compressor blades are situated on
rotors 113. Diffuser 302 is centered between each rotor 113. Fuel
injectors 302 lead to the combustor 109.
[0064] A further advantage of the electrically driven compressor is
that rotational speed of the rotor stages does not suffer from
spool up or spool down time (the time spent increasing or
decreasing the rotational speed of the drive shaft) as is the case
in traditional turbine designs, and the speed of the compressor
rotors 113 can be more quickly adjusted to achieve optimum
performance of the engine based on different flight conditions,
airframe loads, and optimal combustion performance. Polytrophic
efficiencies of the compressor and turbine are expected to be 95
percent or better.
[0065] With each fan blade compressor section being independent of
the other compressor stages may be optimized aerodynamically, and
compressed air ratios, fractional and mass air flow flows can be
optimized to each flight condition (idle, acceleration,
afterburner, cruise, super cruise, deceleration, landing),
maximizing the efficiencies of the compressor. In such
circumstances, the electric compressor turbine engine functions as
a mass-flow dynamic device, separate from the diffuser stages,
combustor 109 and turbine. The electric compressor is ultimately
used as a throttling and engine cycle mechanism, and its velocity
is independent of the turbine engine, but contributes largely to
achieving required compressor ratios for combustion, mass air flow,
by-pass air for thrust, and optimal fuel burn. This permits high
compression ratios and finely tuned air pressures, engine cycle
efficiencies independent of combustion, consistent fuel burn,
effective temperature operation and cooling. Higher energy levels
are achievable, and broader flight envelopes are possible because
the compressor stage acts independently.
[0066] Altitude and temperature constraints are optimized to all
flight conditions. The AHMJET turbine is designed to achieve the
ideal compression, combustion and burn efficiencies at altitude,
and or at sea-level, regardless of air density and moisture, thus
generating higher thrust (and speed) at given altitudes compared to
current generation turbine systems. Because the compressor and
diffuser can be run electrically independent of the turbine, engine
efficiencies and thrust do not have to decline at altitude as the
compression function is now independent of turbine driven function.
Compressor speeds can be controlled independent of turbine output
through electrical power into the Maglev exoskeleton coming from
the Gas Flow Drive.
[0067] High specific thrust occurs at a low cross-section, opening
new airframe integration opportunities. Decoupling the AHMJET
compressor, diffuser, combustor 109 and turbine in an exoskeleton
turbine architecture allows for electrical compressor operation
(powered by the Gas Flow Drive) independent from the diffuser and
turbine, and electrical diffuser operation, separate from the
combustor 109 and turbine; thus enabling the increase in
compression through frictionless high rotating speeds, that are
demanded to dramatically increase air pressure ratios into the
turbine, and increase cooling ratios, which results in higher
combustion efficiencies and thrust, and provides a very wide
operating envelope, thus wide flight envelop for the air
vehicle.
[0068] Combustor exhaust flow remains associated, maximizing energy
for the MHD generator. There is an avoidance of oxygen rich/fuel
lean throttle settings and compressor stall/surge events. AHMJET
gas by-products may be more tightly controlled and reduced in the
Maglev Turbine at high altitudes where typically significant
amounts of CO2 and NOX are produced in combustion. With compressor
function being independent of turbine function, more complete
combustion processes are available; and oxygen rich and/or fuel
lean fluctuations can be avoided.
[0069] The configuration of the invention not only provides thrust
as by-pass air around the combustor 109 but also acts as a
supercharger to the turbine. To achieve a supercharging effect on
the turbine, mass air-flow is accelerated exponentially, in
relation to the velocity of the air in question, at any given rate
of change in time (delta). The supercharging effect upon the
turbine is due to the more optimized pressures (from independent
adjustable rpm on the electrically driven compressor stages, and
now optimized aerodynamics and compressor airfoil designs) now
achievable by the electric compressor, which can be tuned to the
flight condition and altitude for which the electric compressor fan
is designed. The hub or drive shaft is eliminated in this
configuration.
[0070] If electric ring motors 106 are used, the elimination of the
hub portion of the rotor 113 is possible, thus enabling the
generator to be attached to the drive shaft or encased within the
area of what used to be the drive shaft, and located in the space
at the hub of the rotor 113 formerly occupied by the compressor
rotor hub, to which the rotors 113 were connected. The load bearing
surface for the compressor stages is now at the outer circumference
of the compressor stages. This design configuration has not been
done before in an electrical compressor for a flight engine, but
such a design allows for the compressor rotors 113 to be "loaded in
compression," rather than in extension and lower tensile strength
materials such as composites can be used, which leads to a lower
structural weight, lower inertial moments to overcome, and more
effective use of materials and horsepower. Additionally, with the
drive shaft removed in the compressor section and a "donut hole"
available for the generator in the center of the rotor 113,
rotating components in the compressor section of the engine are
induced to less "cyclic fatigue" load producing paths, which result
from the acceleration and deceleration of rotating machinery
attached to drive shafts.
[0071] Massive power generation occurs across all flight regimes
(10.0-12.0 MW+). There is also a reduction of weight through a high
percentage of ceramic matrix composites in exoskeleton. The
invention allows for the reduction in the number of rotor/diffuser
compressor stages (because the compressor cycle can be more
efficiently designed to meet given compression ratios with fewer
stages), which means that the weight of the compressor (and
therefore of the engine) is reduced.
[0072] The configuration of the present invention also leads to the
electrification of auxiliary machinery, and incorporation into the
AHMJET machine interior. Tight airframe integration enables use of
fuel as a heat sink for passive thermal management. High electric
power is present for onboard subsystems and payloads (e.g.,
directed energy weapon).
[0073] The electric distribution architecture between the
compressor combustor, MHD generator is as follows. If the generator
is enclosed within the hollow drive shaft, stationary diffuser
stages (alternating between rotors 113) may act as conductive
pathways to power the ring motor magnetics at the outer rim of each
compressor rotor 113. In this configuration, each compressor rotor
stage is adjacent to an electrical conductive pathway diffuser
stage and can be run independently of the others with motor
controllers 100 at the outer ring of each stage. This configuration
of forming electrical conductive pathways in rotational
turbomachinary components is also novel and unique. This
configuration of the electrical compressor allows for aerodynamic
optimization to meet compression ratios otherwise thought to be
unachievable with a fixed drive shaft driven compressor.
[0074] FIGS. 4A through 4D illustrate exemplary features of the
rotors and stators of the preferred embodiment of the present
invention. FIG. 4A shows a three-dimensional view of the
rotor/stator section of the turbine. The rotors 113 are shown
circumferentially bordering the air inlet 107. FIG. 4B contains an
enlargement 400 of a section B wherein an inward air thrust 401
moves against rotor 113. The rotor direction 402 is perpendicular
to that of air thrust 401. Adjacent to the rotor is the
stator/diffuser 303. FIG. 4C shows the frontal view of the three
dimensional view presented in FIG. 4A. An illustration of the
compressor stage is presented in FIG. 4D, in which the section
enlarged in FIG. 4B is contained.
[0075] The electric compressor can house a magnetic air bearing
between each compressor stage (rotor 113) and diffuser (diffuser)
in the compressor trunion. The electromagnetics are embedded and
integrated into the outer ring of each compressor stage (rotor 113)
and electricity passes across a magnetic flux generated at the
rotor compressor/diffuser interface propelling that compressor
stage. AC current is produced in a conductive hot exhaust flow from
the turbine via magneto hydrodynamic drive (MHD). The magnetic flux
created from a seeded conductive hot, high speed jet exhaust
passing conductive magnetic plates 117 in the exhaust nozzle casing
increases exponentially with the hot gas exhaust velocity with
kilowatt levels of power produced. Hot gas combustion is seeded
with a positively charged seeding ion (e.g. selenium) in powder
form stored on board the air vehicle. The combination of conductive
hot gas exhaust generating a powerful magnetic flux by passing an
embedded arrangement of magnetic plates 117 in the jet nozzle wall
to power the electric compressor at the front of the turbine is
unique and novel.
[0076] Electric power is fed from the embedded magnetic plates 117
of the exoskeleton to the inner wall of the stationary shaft-less
diffuser stages, driving the air bearing (maglev) suspended
adjacent compressor stages. The shaft-less "donut hole" becomes a
cooling channel to dissipate heat via convection and radiation
generated by the magnetic flux interface of the rotating rotor
stage (compressor) passing the conductive stationary diffuser
stage. The electric compressor in this iteration is the generator.
It is driven by electric power generated by magneto hydrodynamic
drive (MHD) in the turbine via seeding the hot exhaust with a
conductive ion.
The Design Approach
[0077] Increased performance and weight costs down has been the
focus on gas turbine technology development in the last 20 years
(Integrated High-Performance Turbine Engine Technology--IHPTET
Program). Government and military supported programs have focused
on ceramic components for the hot section components of gas turbine
engines where they enable higher turbine inlet temperatures and,
therefore, higher thermal efficiencies. However, these development
programs have focused on 50 year old gas turbine technology, rather
than a clean "sheet design approach", integrating propulsion and
electric generation systems providing the potential of very high
thrust capabilities, energy generation, and an order of magnitude
increase in propulsion efficiency across future flight regimes of
multi-mission aircraft.
[0078] The DOD and Armed Services are now demanding significant
increases in electric output from in turbine flight engines, from
5.0 Megawatts to 20.0 Megawatts, to power on-board energy weapons
and all electric aircraft subsystems. Currently, US Air Force, Navy
and Army Aviation requirements for future unmanned and manned
systems are demand propulsion capabilities which do not exist yet
or are in research and development phase. These propulsion
requirements are for rapid acceleration from subsonic to sustained
hypersonic speeds (Mach 0.3-Mach 5.8+) for long range deep strike
and persistence capability, delivering high power electric energy
for Directed Energy Weapons (DEW), all electric aircraft
subsystems, and managed through sophisticated electric power
management architectures for aircraft function.
[0079] In the traditional layout form of a compressor, combustor
109 and turbine propulsor, dynamic components are so designed to be
in tension, with heavy axially loaded drive shafts, and gear boxes,
which form the basis of limited thrust to weight ratios typically
in the order of no more 5-6 to 1. Turbomachinary design, therefore,
to increase performance, just in terms of weight, must turn to
machine systems where light weight hollow-core structures using
highly alloyed single crystal titanium materials can be used, and
lightweight high temperature ceramic matrix composites (CMC)
materials can further enhance weight savings. In order to do so,
these materials must be designed into a favorable, but highly
loaded, dynamic turbomachinary component operating environment. The
operational environment (temperature, pressure, speed) is one where
the material benefit of single crystal metal alloys and CMC's may
be observed. Thus, the starting point for turbomachinary design
must put rotating dynamic systems components
(compressor-stator/rotor 113, turbine, and gas generator) which are
normally in extension, into compression.
[0080] To achieve this design point the turbine concept is turned
"in-side out (an exoskeleton turbomachinary design)". In such a
configuration the drive shaft can removed and the associated weight
with it. The medial end of all the turbomachinary components are
attached to a lightweight CMC or titanium load ring, and the load
bearing structure is moved to the outer casing. The distal end of
the rotating turbomachinary components in this concept are
integrally molded with CMC structure, or fusion welded in the case
of single crystal alloy titanium, to the magnetics trunion case
which faces the coil and magnet outer casing wall (to be discussed
further on in this paper).
[0081] The AHMJET of the present invention demands that a
bearing-less, load bearing structure is used to reduce weight,
electromagnetics technology is embedded within it, and air bearing
technology (magnetic levitation) is utilized to provide a
frictionless magnetic levitation loaded surface to suspend the
rotating compressor, diffuser and turbine from the outer casing
wall in the AHMJET concept. Magnetic levitation air bearing
technology in this concept works on the principle of a series of
magnets embedded in the outer structural casing of the rotating
compressor (rotor 113/stator) and turbine using embedded composite
neodium/boron permanent magnets of opposing magnetic flux and
propulsion coils in the outer loaded casing, generating opposing
magnetic forces.
[0082] An outside power source is used to start the AHMJET turbine
system. Current is AC, and can be redirected into DC current so
that the magnetic levitation component also generates electricity.
The ground power source is removed once the turbine reaches
combustion at idle and the compressor/turbine is rotating and
generates electricity to the magnetic air bearing, suspending the
engine core. Energy density and generation capacity can be
extremely high since rotational speeds may now be very high (60,000
to 80,000 rpm for a 30,000 lb. thrust prototype turbine) at the
outside of the exoskeleton non-bearing surface, where the permanent
coils and permanent magnets are located. The gap between the
surfaces is very small, less than 1 mm. The exoskeleton AHMJET
turbine concept is self-perpetuating and sustaining. It's two
functions are to provide a large compression load bearing surface,
and to generate electricity.
[0083] In order for magnetic levitation to work power to the coils
embedded in the outer casing of the exoskeleton must be an opposed
charge to the composite neodium/boron permanent magnets of the
rotating components embedded in the trunions (distal end component
structures of the rotor 113/stator and turbine) to suspend these
rotating turbomachinary components from the outer wall casing, with
all directional centrifugal loads in compression.
[0084] To exploit an exoskeleton turbine design ceramic components
can be substituted for metal components with only minor design
changes to accommodate the brittle failure mode of ceramics. This
reduces weight and allows for design of the thermal cycle and
combustion temperatures to be higher than current turbine
technology because of the higher thermal cycle material
characteristics of ceramics. Higher thermal cycle temperatures
produce higher thermal efficiencies and reduce fuel burn at the
same thrust levels allowing for greater combustor, and thus
propulsion efficiency. The compressive strength of ceramic
materials which can be used in the compressor and diffuser vane,
stators, and turbine blades are typically a factor of 10 higher
than the tensile strength, suggesting the adoption of designs in
which rotating ceramic components go into compression as they
spin-up, this further benefits weight reduction of turbine
components.
[0085] This advanced materials design approach suggests using
ceramic blades placed on the inside of rotating cylinders rather
than blades attached to a rotating shaft. An engine of this design
is referred to as either "exoskeleton" or "inside-out" designs.
Novel compression and combustion machine designs in AHMJET are
possible because of the use of CMCs including: utilization of air
or magnetic bearings; radial staging of rotor 113 and stator
(compressor) sections; and high power density ring motors 106 and
generators to power fan and compressor stages, and generate power
from turbine sections and magneto hydrodynamic drives to operate
the ring motor bypass fans and compressor. Accommodation of
steady-state and transient thermal stresses is particularly
important in ceramic engine components. Exploiting rapid
prototyping methods that build ceramic or metal components without
part-specific tooling and which can be modified to spatially
control composition, is useful in producing surface compressive
stresses and thermally insulating surface layers.
[0086] Commercially available gas turbine engines in this power
range are typically less than 35% efficient. This design approach
could allow for efficiencies in the 40%-45% range as ceramic
designs in compression provide higher thermal efficiencies, higher
operating temperatures, and higher rpm (60,000-80,000 for
bearing-less magnetic levitation) generation motors reduce friction
to zero (parasitic drag approaches zero), increasing energy density
and increasing watts per horsepower of electric generation (1200
watts/HP vs. 740 watts/HP). As thrust is more independent of energy
generation due to a non-mechanical design in AHMJET (shaft-less
design and MHD gas drive generator) thus thrust losses are
minimized. Since power density of electric propulsion-motor
generators, as with AHMJET, increases with rotational speed, this
Maglev gas turbine can be particularly effective as both a
propulsion energy generation system.
[0087] A detailed description of the stages of the operation of the
jet-electric turbine of the present invention will be presented
below with reference to the drawings.
[0088] The preferred embodiment of the present invention
incorporates a dual intake 120 at the fan face of the AHMJET
turbomachinary, as set forth in FIG. 1. Air is taken in at the fan
face of the compressor, and in the central "donut hole" tunnel,
which the forms the I.D. of the exoskeleton. The "donut hole"
tunnel becomes the scramjet inlet above a calculated velocity of
2.8 Mach to sustain hypersonic combustion (combustion occurs with
fuel due to pressure and velocity of the air at the combustor 109)
rather than turbine machinery combustion. The compressor stages are
made up of a rotor 113 and stator 115 which are "de-coupled"
electrically through the AHMJET segmented "bearingless"
exoskeleton. This stage electrically "de-coupling" allows for air
compression, air velocity, air pressure differential (diffusion)
and air-fuel mixing to be managed more sequentially in terms of
pressure ratio creation and optimization prior to the combustion
stage, and subsequent turbine operation for thrust.
[0089] The AHMJET technology of the present invention involves the
evaluation of a 35,000-40,000 lb. thrust electric turbo machine.
This further involves integrating other propulsion technology
concepts into turbomachinary propulsion, and combustion
thermodynamics, taking the approach of new baseline design
integration and turning the engine inside out. The compressor
increases the pressure of the incoming air so that the combustion
process and the power extraction process after combustion can be
carried out more efficiently. By increasing the pressure of the
air, the volume is reduced, which means that the combustion of the
fuel/air mixture will occur in a smaller volume.
[0090] The compressor functions as a separate mass dynamic flow
stage because of the ability for electric coupling and de-coupling,
from the turbine, by ways of the magnetic air-bearing, MHD gas
generator, and propulser. Thus, where turbines function on the
ratio of compressed air achieved from ambient air densities, to
achieve combustion, rather than air velocity, the compressor in the
AHMJET design is used as a throttling and engine cycle mechanism,
fine tuning air pressure, air velocity, engine cycle, temperature
and cooling. Higher energy levels are achievable by the AHMJET
driven compressor stages advancing at higher rpm's than the turbine
(compared to current technology where the compressor runs at the
same speed as the turbine because both are attached to the same
drive shaft), driven by the electric power coming from the MHD gas
generator behind the turbine and conducting plates in the exhaust
stream.
[0091] The rotating stall may consist of one or multiple cells that
rotate around the compressor at an angular speed which is a
fraction of the rotor speed. This instability results in a loss of
compressor performance that may require the shut down of the engine
to clear. Operating a compressor in rotating stall can contribute
to fatigue damage of the blading resulting from the rotating stall
unsteady aerodynamic loading. Also, the loss in performance due to
rotating stall can also move the compressor to an operating point
where surge is initiated.
[0092] The AHMJET technology of the present invention can avoid
surge conditions since the compressor stages are run individually.
Each has an electromagnetic motor drive, is shaftless, and is
suspended in electromagnetic equilibrium with the magnetic
levitation air bearing conceived in the trunion and turbine outer
exoskeleton. Individual rotor and stator stages, controlled
independently and air pressure and thermal temperatures monitored
with embedded sensors is the preferred prevention design of AHMJET
as it relates to compressor stall and surge. Compressor stages can
be sped up or slowed down in AHMJET accordingly to manipulate mass
airflow and avoid onset of surge and over spinning of RPM.
[0093] The Euler Equation is used to describe the flow of a
calorically perfect gas through a centrifugal flow compressor as is
the case for compressor stages in the AHMJET engine with axial gas
flow entering such that: Tt3-Tt1=v2Ut/GcCp Equation 1
[0094] Ideally, the fluid, or gas leaving the rotor wheel has a
swirl velocity v2 equal to the rotor 113 speed Ut. Due to slip
between the rotor 113 and fluid (or gas) the fluid leaving the
rotor wheel attains only a fraction of the rotor speed. The ratio
of the exit swirl velocity to the rotor speed is called the slip
factor "e". "e"=v2/Ut Equation 2
[0095] The slip factor relates to the number of vanes on the rotor
113 of the electric compressor and its stages in the AHMJET. As the
number of vanes "n" increases, the slip factor approaches 1 and the
frictional losses of the rotor 113 increase. In the AHMJET design
there are no mechanical bearings, only magnetically levitated "air
bearings", therefore frictional losses are almost zero and vane
numbers on the rotor 113 may be increased to raise the compression
ratio to higher ratios than seen in traditionally designed shaft
turbines (as compared to shaftless turbines as in AHMJET. Selection
of the number of vanes in relation to AHMJET comes down to a high
slip factor approaching 1, and frictional losses are not accounted
for and formed to a constant of "0". A useful numerical correlation
between the slip factor "e" and number of vanes "n" is "e"=1-2/n
Equation 3
[0096] Or as in the case of a frictionless magnetically levitated
ring motor driven compressor stage made up of rotor 113 (vanes) and
stator: "e"=1>or=2/n Equation 4
[0097] Substitution of Equation 2 into Equation 1 gives a
relationship of compressor temperature rise in terms of the rotor
speed Ut, and the slip factor "e". Tt3-Tt1=eU2t/GcCp Equation 5
[0098] By using a polytrophic compressor efficiency Ec and Equation
5, the compressor pressure ratio can be expressed as
Mc=Pt3/Pt1=(1+EU2t/GcCpTt1) to the order of the power: Yec/(y-1)
Equation 6
[0099] From Equation 6 compressor pressure ratio Mc can be plotted
versus rotor speed Ut for air<y=1.4, Cp=1.004 Kj/(kgK)>at
standard conditions (Tt1=288.16 K) with a slip factor "e" of
0.9999. For rotors 113 of light alloys this high slip factor is not
possible, and one of 0.8-0.9 is only possible with rotor speed
maximums of about 1500 ft/second, by the maximum centrifugal
stresses of the rotor 113 with subsequent corresponding compressor
pressure ratios of about 4.0. With the AHMIET technology with the
"exoskeleton" shaftless design, with magnetically levitated "air
bearing" rotors/stators 113 (description of a single compressor
stage being of a rotor/stator, of which in the described design
there are eight) can be manufactured of actively cooled, "hollow"
hafnium carbide, fiber reinforced, ceramic matrix composites as
centrifugal forces do not exist as the rotors/stators are in
compression, not extension where centrifugal forces originate
from.
[0100] Hence compressor and rotor speeds may be increased to 2500
ft/sec.-3000 ft/sec. almost double with higher blade count and
lighter higher temperature materials (fiber reinforced ceramic
matrix composites) and subsequent higher compressor pressure ratios
in the range of 10.0-12.0. These very high compression ratios are
only attainable where rotor speeds can be raised dramatically and
the slip factor can be brought up to 1.0. The only way to achieve
this is to put the turbomachinary components in compression (not
extension) with a shaftless design and then high rotational speeds
are possible with compressor ratios 40% -50% higher than in current
state of the art designs.
[0101] The design of multistage axial compressors is mainly based
on 2D-methods, in the case of this design approach 8-stage
compressors will be evaluated. In order to gain increased Mach
number levels and reduced profile losses, controlled diffusion
airfoils (CDA) are realized in this new turbo machine design
concept. The close relation between unsteady flow effects and loss
prediction is well known in diffuser design dynamics (Schulz 1990).
Large stator hub corner stall cells occur with traditional turbo
machine design and are even observed under steady conditions, along
with wakes and periodic fluctuations generated in front of the
stator. In the AHMJET turbine concept there is no large center hub
to create corner stall, as the design concept is shaftless, thus
separation regions do not occur due to there being none existing in
the design. Typical end wall losses are eliminated as the diffuser
rotates against the outer wall exoskeleton casing by being embedded
in the trunion anode of the AHMJET section of the compressor. Also,
unsteadiness in the boundary layer and from clearance vortices is
eliminated as the diffuser is one integral component, the rotor 113
and stator tied integrally to the AHMJET outer exoskeleton trunion.
Diffuser clearance is a non issue (diffuser integral to exoskeleton
trunion wall), which typically has contributed to large mass flow
production losses, with heavy impact on main air flow.
[0102] This behavior is caused by high blade loading due to
positive incidence angles and a high inlet Mach number as design
speed is maximized. Now blade and diffuser loads are concentrated
in a distributed compressive force, not one of tension as with
shafted turbines. Characteristic rise of suction side profile
losses for CDA-blading is minimized as diffuser stages/compressor
stages are electrically phased in-or-out during run times,
maximizing engine cycle efficiencies and reducing aerodynamic
losses. The best efficiency with 90.9% can be found at 94% speed.
While at lower speeds the stage matching gets worse and avoids a
better performance of the machine, higher speeds cause the increase
of circumferential velocity and Mach number level with the
consequence of decreasing efficiency.
[0103] The burner sits between the compressor and the power
turbine. The burner is arranged like an annulus, or a circular
doughnut. In this concept the burner combines the benefit of an
annular combustor 109 with the liner sitting inside the outer
casing and atomizers are so designed to maximize separation between
fuel molecules and low velocity swirl. This swirl characteristic
provides control of the flame front, marginalization of combustion
temperatures down the length of the combustor 109, and effective
mixing of core bypass air doming from the shaftless center of the
turbine.
[0104] Stators 115, also known as guide vanes, control mass air
flow onto the turbine disks at the correct angle to maximize the
airflow, maximizing thrust. Guide vanes are designed to absorb all
the pressure and temperature fluctuations coming from the combustor
109 in order to get the most out of the airflow and meet engine
operating and design requirements. They establish laminar airflow
from turbulent flow from the end of the flame front to the first
turbine blisk (disk, power turbine, by-pass air and annulus cooling
air of the combustor 109)
[0105] A multi-stage, 4-stage configuration is desired to maximize
thrust and efficiency. Based on a proposed engine class of 20,000
lbs., twelve turbine stages are incorporated into the present
invention with eight compressor stages. The turbine is supported on
the inner shaftless ring drive and the outer trunion casing,
rotating freely within the magnetic field of the AHMJET system.
[0106] The exhaust cone 112 houses the magnetics 117 and 118, coils
110 and seeding flows 104 for alkaline distribution to charge the
high velocity exhaust flow for the Gas Flow Generator (MHD).
Seeding will occur just upstream of the last turbine stage where
velocity is lower. The exhaust 112 maintains velocity flow from the
last turbine stage to the end of the exhaust cone. Afterburner
capability could be possible, integrated into the fuel feed
upstream at the combustor 109.
[0107] The trunion casing 114 extends the lengths of the
turbomachinary where there are dynamic rotating components, this
includes the compressor, stator/diffuser 115, turbine and MHD. It
contains integrally the distal ends of all the shaftless turbine
components. The trunion houses the magnetics for the Maglev
Systems.
[0108] The Maglev Turbomachinary consists of an inner and outer
exoskeleton. A generated magnetic field from the Gas Flow Generator
(MHD) suspends the inner turbine core from the outer
magnetized/coil outer casing to a tight tolerance (approx. 1
mm)
[0109] Figured-8 levitation coils are installed on the inside
sidewalls of the outer casing. This arrangement comes form Maglev
trains and provides a high level of inductance. When the neodymium
iron boron permanent magnets embedded in the compressor, diffuser,
turbine section trunions holding the distal ends of the rotating
components, pass at high speed and in close tolerance above the
center of these coils, an electric current is induced within the
coils, which then act as electromagnets, as a result, there are
forces which push the superconducting magnets in the compressor
case trunion (and all inner ceramic rotating components which are
integral to the trunions) and simultaneously center it and levitate
it.
[0110] The magnetic air bearing is designed around two separate
criteria. To provide the shear pressure necessary to meet the power
requirement and establish a magnetic bearing capable of meeting
axial, in-plane and out-of-plane loads .Two basic designs for the
magnetic bearing are considered here. An active bearing for control
through algorithm software sensor controls to the FADEC (full
authority digital engine control) is used against the generated
electromagnetic fields, manipulated by an embedded controller 100
tied to the algorithm software through aerodynamic eddy-current
sensors, pressure sensors in each compressor ring motor and/or
turbine generator ring motor.
[0111] A ground based power supply is used for starting until the
MHD gas generator in the turbine generates enough electricity to
run the electric compressor/magnetic air bearing fore and aft, and
the AHMJET is self sustaining. The levitation superconducting coils
are connected all the way around the inside perimeter of the outer
stationary turbine casing. In operation of the AHMJET system, a
repelling force between the turbine rotating component trunions and
the outer casing guide way keeps the rotating component sections at
the center of the outer casing. The stator coils embedded in the
outer casing guide ways will be designed using superconducting
wire. Several chemical combinations are possible in the AHMJET
design which are novel and have not been done before in magnetic
turbine machinery using superconducting wire. YBCO, for its
constituent elements: yttrium, barium, copper, and oxygen will be
explored as a superconductor coil. Hybrid superconducting magnetic
materials, such as neodymium iron boron permanent magnets shall be
explored which shall be implemented into the compressor, diffuser,
turbine section trunions holding the distal ends of the rotating
components.
[0112] The superconducting/electromagnetic hybrid bearing will be
designed using active radial electromagnetic positioning and a
superconducting passive axial levitator technology. The design
approach would use a multi-pole design, the number of which will be
defined by the electromagnetic density an d the axial length of
each compressor stage and turbine stage which will be constrained
by the lass air-flow of the design. Two-phase induction machine
design using specially designed stator windings for delivering
torque and radial positioning simultaneously will be utilized for
positioning control. The radial bearing will use four eddy-current
sensors, displaced 10.degree. from each other around the 360 degree
circumference of the casing, for measuring the shaft position and a
PID control system for feeding back the currents.
[0113] An electronic control algorithm will be used for the
companies ring motor technology which shall be derived to a
mathematical derivative to control the clearance tolerance so that
it remains constant to a nominal 1.0 mm, +/-0.1 mm. The levitation
system is supplied from an off-board ground station to start, until
electric generation capacity from the MHD in the combustor
109/turbine section supports the electric compressor/air bearing
requirements. Beyond startup the AHMJET is self sustaining for its
electrical requirements.
[0114] The synchronous long stator linear magnetic motor is used
both for propulsion of the rotating trunion exoskeleton inside the
casing and for magnetic levitation (air bearing) of the trunion
structure away from the outer casing wall. It functions like a
rotating electric motor whose stator is cut open and stretched
along the circumference of the inside of the exoskeleton. Inside
the motor windings, alternating current is generating a magnetic
traveling field which moves the compressor, diffuser or turbine
component trunions of the exoskeleton, levitated and propulsed
inside the outer casing. Support magnets in the trunions function
as the excitation portion (rotor 113).
[0115] Speed can be continuously regulated by varying the frequency
of the alternating current. If the direction of the traveling field
is reversed, the motor becomes a generator and provides additional
power off the turbine and adds to the MHD capacity. Braking energy
can be realized as the turbine speed is slowed as necessary through
the flight regime (i.e. during landing, loiter, etc.) by fuel burn
adjustment and can be re-used and fed back into the electrical
turbine network through a proprietary capacitance energy storage
bank technology.
Magneto Hydrodynamic Drive of the Exoskeleton Turbine
[0116] A magneto hydrodynamic drive (MHD) generator is used to
electrify the hybrid exoskeleton turbine and airframe, providing
high power for the magnetic air bearings (magnetically levitated
compressor of 8 stages, and turbine generator, of 4 stages) and
directed energy weapons, and all electric sub-systems on board the
aircraft.
[0117] The MHD generator is established with concentric magnetic
coils at the diverging exhaust nozzle of the engine. Because the
exhaust gases passing through the nozzle are in an ionized
condition, it is possible to generate an electric current.
Typically the higher the mach number of the gas exhaust, the more
electric power that can be produced from the free gas stream. There
are a variety of gases with a chemical compound containing an
alkaline metal to make conductive plasma within the stream. Seeding
the working free gas stream with small concentrations of potassium
or selenium provides the necessary number of free electrons to
generate electric power from the MHD. The seeding density is
calculated from the exhaust gas flow velocity, exhaust temperature,
and the time across a specific mission envelope of which this
engine would be utilized in. Other possible seeding materials for
this application having a relatively low ionization potential are
the alkali metals, cesium or rubidium. An MHD generator, like a
turbo generator, is an energy conversion device and can be used
with any high-temperature heat source-chemical, nuclear, solar,
etc.
[0118] The production of electrical power through the use of a
conducting fluid moving through a magnetic field is referred to as
magneto hydrodynamic (MHD), power generation as aforementioned
earlier. When an electrical conductor is moved so as to cut lines
of magnetic induction, the charged particles in the conductor
experience a force in a direction mutually perpendicular to the B
field and to the velocity of the conductor. The negative charges
tend to move in one direction, and the positive charges in the
opposite direction. This induced electric field, or motional emf,
provides the basis for converting mechanical energy into electrical
energy. At the present time nearly all electrical power generators
utilize a solid conductor which is caused to rotate between the
poles of a magnet.
[0119] Because MHD power generators do not require the use of
moving solid materials in the gas stream, they can operate at much
higher temperatures than other types of electric generation
machines. Calculations show that a gas fired (Jet-A, Kerocene,
hydrogen) MHD generator designed to the AHMJET technology may be
capable of operating at efficiencies between 40 and 50 percent.
[0120] The essential elements of a simplified MHD generator,
typically referred to as a "Continuous Electrode Faraday
Generator", are a field of magnetic induction B applied transverse
to the motion of an electrically conducting gas, flowing in an
insulated duct with a velocity u. Charged particles moving with the
gas will experience an induced electric field, u.times.B, which
will tend to drive an electric current in the direction
perpendicular to both u and B. This current is collected by a pair
of electrodes, or in the case of the AHMJET Technology, embedded
magnetic plates 117 internal to the wall of the combustor 109 and
exhaust duct, on opposite sides, in contact with the gas and
connected externally through a load. Neglecting the Hall effect,
the magnitude of the current density for a weakly ionized gas is
given by the generalized Ohm's law as; J=u(E+u.times.B).
[0121] Where:
[0122] Motion of an electrically conducting gas flowing at velocity
1000 m/sec=U;
[0123] Field of magnetic induction=B;
[0124] Induced electric field, perpendicular to both u and B, of
charged particles=U.times.B;
[0125] Electrical power delivered per unit volume load of an MHD
generator gas=P;
[0126] Magnitude current density of ionized gas is given by Ohm's
law J=u(E+u.times.B);
[0127] Coordinate system of an open circuit of AHMJET MHD is
Jy=0;
[0128] Open circuit electric field=uB;
[0129] Electric field in the "Y" direction of the coordinate system
is=Ey=0;
[0130] Theta is a constant and is uniform thus="a";
[0131] Short circuit current is Jy=-auB;
[0132] The loading parameter where K is the load of the
current=Ey/uB;
[0133] Electric power delivered to the load per unit volume of the
AHMJET MHD is P=-JE (negative sign denotes that the conventional
current flows in the negative Y direction);
[0134] The electric power delivered to the load per unit volume for
the generator shown in FIG. 1. is P=au2B2K (1-K), where
(2=squared); and
[0135] Power density maximum value is: Pmax=au2B2/4.
[0136] The electric field E, which is added to the induced field,
results from the potential difference between the electrodes. In
the case of the AHMJET technology the potential difference is the
surface area, A, times the axial length, Al, of the conductor
magnetic plate, which defines the volume, of which the velocity, V,
of the plasma (charged ion gas) moves through it, creating an
induced field resulting from the potential difference between the
anode and cathode (electrodes). Since the AHMJET magneto
hydrodynamic drive is basically a segmented Faraday generator,
(four magnetic plates on either side of the plasma flow making up
the anode and cathode) and extend the entire length of the exhaust
duct, they tend to impose a equipotential surface in the gas which
are normal to the y-direction. For the purposes of discussion in
this section on the MHD drive of AHMJET, we shall assume that both
u and u are uniform. In terms of a coordinate system, we have that;
Jy=u(Ey-uB).
[0137] Because the electrodes in a MHD generator of this type for
the AHMJET Technology extend the entire length of the duct, they
tend to impose equipotential surfaces in the gas which are normal
to the y-direction. In accordance with the above equation the
electrical power delivered to the load per unit volume of the MHD
generator gas proposed in this application is; P=-JE.
[0138] It follows that J=-E'=-O'uB(l-K) y 1+p2 y 1+p2'-pO'
[0139] The Hall effect reduces J y and P by the factor (1+P2) and
results in the appearance of a Hall current which flows downstream
in the gas and returns upstream through the electrodes. The
reduction of J y and P is caused by the fact that the uB field must
overcome not only the Ey field produced by the electrodes, but also
the Hall EMF (electrode magnetic frequency) resulting from the
current flow in the x-direction.
[0140] To circumvent the deleterious consequences of the Hall
effect, the electrodes may be segmented in such a manner that
separate loads occur connected between opposed electrode pairs. In
the limit of infinitely fine segmentation, there can be no
x-component of current either in the electrode, or in the gas, and
so the condition for an ideal segmented MHD Faraday generator in
AHMJET is; J.times.=0.
[0141] For the generator, P=uu2B2K(1-K). This power density has a
maximum value for K=1/2. In accordance with the equation above, the
rate at which directed energy is extracted from the gas by the
electromagnetic field per unit volume is -00 (J.times.B). We
therefore define the electrical efficiency of a MHD generator as;
JoEl1e=0(J.times.B).
[0142] For the generator being discussed, l1e=K. The Faraday
generator therefore tends to higher efficiency near open circuit
operations as in AHMJET. In order that the MHD generator have an
acceptable size and use in this application, The generator should
deliver a minimum of about 2.0 MW per cubic meter of gas. Power
generation is then directly relational to the sized volume of the
exhaust 112 and the exhaust velocity, thus the design limit is in
terms of shaft horsepower of the core turbine. This brings back to
focus the core concepts of reducing weight, reducing the number of
core rotating components, raising core operating temperatures,
raising burn efficiencies, and using a segmented turbine with
electric phased-lock design operation so the staged AHMJET
operating engine conditions can be maximized across the entire
flight envelope; ultimately generating 1.5-3.0 times the thrust to
weight above traditional turbine designs. In accordance with
equation (4.4), the rate at which directed energy is extracted from
the gas by the electromagnetic field per unit volume is
-00(J.times.B). We therefore define the electrical efficiency of a
MHD generator as; JoEl1e=0(J.times.B).
[0143] Current densities are anticipated to be in the order of a
few amperes per square cm or more, when baseline electric power
requirements are set at 12.0 MW, with predicted gas flow rates at
average speeds of Mach 3.8, the point of transition whereby turbine
compression is switched off and combustion all occurs in the center
"donut-hole" inlet and supersonic/hypersonic combustor 109. From
preceding research with MHD and steam fired turbine generators
equilibrium electrical conductivities at atmospheric pressure with
potassium-seeded combustion plasmas, and/or potassium-seeded or
cesium-seeded argon plasmas, gas temperatures needed to achieve the
condition of 3-5 amperes per square centimeter and 10 MW per cubic
meter of gas can be readily obtained from Jet-A, Kerocene and other
fossil fuels.
[0144] Given known values of the electron Hall parameter for a
magnetic induction electrical current, corresponding to gases and
conditions in a steam fired or fossil fueled turbine combustor 109
it is apparent that the Hall effect can play a significant role in
the operation of an MHD generator. Because of the Hall effect, a
current flowing in the y-direction can give rise to a current
flowing in the x-direction. Thus Ohm's law is expressed as: the
form of equation (9.1), we must now write Jy=(E+PEx)
[0145] or rearranging 1+''and Jx=(Ex-PE).
[0146] To meet the magnitude of power needing to be generated for a
superconducting light weight airborne laser electrodes in the
turbine duct must extend the entire length of the duct. Thus they
tend to impose equipotential surfaces in the gas which are normal
to the y-direction. Thus for a continuous electrode Faraday
generator we have: Ex=0, thus following,
J=-E'=-O'uB(I-K)y1+p2y1+p2'-pO', Jx=i+p2Ey=-Ply,
[0147] Thus rearranging O'u2B2p=i--:+p2K(1-K).
[0148] The Hall effect reduces J y and P by the factor (1+P2) and
results in the appearance of a Hall current which flows downstream
in the gas and returns upstream through the electrodes. The
reduction of J y and P is caused by the fact that the uB field must
overcome not only the Ey field produced by the electrodes, but also
the Hall emf resulting from the current flow in the x-direction. To
circumvent the deleterious consequences of the Hall effect, the
electrodes thus may be segmented in the design approach, and
separate loads connected between opposed electrode pairs. In the
limit of infinitely fine segmentation, there can be no x-component
of current either in the electrode or in the gas, and so the
condition for an ideal segmented Faraday generator is:
J.times.=0.
[0149] Described herein is a higher performance MHD generator for
directed energy weapons, microwave weapons that can be fired
synchronously through this high electric generation power source
thereby mitigating engine failure rates, vibrations, and costs,
while at the same time, increasing survivability and operability.
This MHD generator will be capable of providing both the power
required for the onboard directed energy weapon system and high
performance flight speeds and transition across multiple mMach
regimes; subsonic, supersonic and hypersonic.
[0150] It is shown that in certain cases the Joule heating in a
magneto hydrodynamic generator is sufficient for the electron
temperature to be raised above that of the heavy gas particles. The
practical application of the resulting increase in ionization and
hence electrical conductivity is discussed. When an electrical
conductor is moved so as to cut lines of magnetic induction, the
charged particles in the conductor experience a force in a
direction mutually perpendicular to the B field and to the velocity
of the conductor. The negative charges tend to move in one
direction, and the positive charges in the opposite direction. This
induced electric field, or motional emf, provides the basis for
converting mechanical energy into electrical energy. At the present
time nearly all electrical power generators utilize a solid
conductor which is caused to rotate between the poles of a magnet.
In the case of hydroelectric generators, the energy required to
maintain the rotation is supplied by the gravitational motion of
river water.
[0151] Turbo generators, on the other hand, generally operate using
a high-speed flow of steam or other gas. The heat source required
to produce the high-speed gas flow may be supplied by the
combustion of a fossil fuel or by a nuclear reactor (either fission
or possibly fusion). The production of electrical power through the
use of a conducting fluid moving through a magnetic field is
referred to as magneto-hydrodynamic, or MHO, power generation.
Magnetic Levitation of the Exoskeleton Turbine
[0152] Figured-8 levitation coils are installed on the inside
sidewalls of the outer casing. When the superconducting magnets
embedded in the compressor, diffuser, turbine section trunions
holding the distal ends of the rotating components, pass at high
speed above the center of these coils, an electric current is
induced within the coils, which then act as electromagnets. As a
result, there are forces which push the superconducting magnets in
the compressor case, diffuser and turbine trunions, and
simultaneously center it and levitate it. A ground based power
supply is used for starting until the MHD in the turbine generates
enough electricity to run the maglev fore and aft, and the AHMJET
is self sustaining. The levitation coils (magnets) are connected
all the way around the inside perimeter of the outer stationary
turbine casing.
[0153] The guidance magnets located on the rotating component
trunions, and the embedded superconducting coils in the engine
casing walls keep the shaft-less rotating component machinery
laterally on the track inside the exoskeleton wall. The levitation
system is supplied from off-board ground station to start, until
electric generation capacity from the MHD in the combustor
109/turbine section supports the maglev electric requirements.
Beyond startup the MMHET is self sustaining for its electrical
requirements. The synchronous longstator linear magnetic motor is
used both for propulsion of the rotating trunion exoskeleton inside
the casing and magnetic levitation (air bearing). It functions like
a rotating electric motor whose stator is cut open and stretched
along the circumference of the inside of the exoskeleton. Inside
the motor windings, alternating current is generating a magnetic
traveling field which moves the compressor, diffuser or turbine
component trunions of the exoskeleton, levitated and propulsed
inside the outer casing. Support magnets in the trunions function
as the excitation portion (rotor 113). Speed can be continuously
regulated by varying the frequency of the alternating current. If
the direction of the traveling field is reversed, the motor becomes
a generator and provides additional power off the turbine and adds
to the MHD capacity. Braking energy can be realized as the turbine
speed is slowed as necessary through the flight regime (i.e. during
landing, loiter, etc.) by fuel burn adjustment and can be re-used
and fed back into the electrical turbine network.
Operation of the AHMJET System
[0154] The following stage of operation description defines the
AHMJET technology from an engine systems perspective covering
compression, ignition, combustion, flame management, MHD electric
generation, power architecture, magnetic levitation and subsonic,
supersonic and hypersonic transition. In essence, the staged
operation running of AHMJET is a seamless technology approach
toward the creation of a hybrid propulsion system that covers all
propulsion needs across all flight regimes.
Initiation of Combustion: Entropy and Enthalpy
[0155] The gas turbine engine combustor 109 increases the enthalpy
of the working fluid by oxidization of fuel and the subsequent
dilution of the resulting products with additional air until
temperatures acceptable to the turbine are achieved. From an
operability viewpoint, the combustor 109 must provide a flow
environment that is conducive to both ignition and the stability of
the flame over a wide variety of engine operating conditions.
Steady performance requirements are more easily met with AHMJET
because each compressor stage performs individually to a specific
thermal profile and compression ratio target as they are all
segmented electronically in the shaftless drive exoskeleton and are
not connected to one another. Additionally the electric compression
portion of the AHMJET more readily is controlled and meets the
steady performance requirements for combustion, acceptable exit
temperature profiles, low-pressure losses and minimal pollutant
emissions are necessary.
[0156] CFD gas turbine combustor modeling has generally been
limited to isolated parts of the combustion system. Reacting flows
inside the combustor liner are more easily controlled with the
assumed profiles and flow spits at the various liner inlets in the
AHMJET annular combustor 109, and exoskeleton cooling from the
by-pass air. Pattern factors, emissions and combustion efficiencies
are more easily controlled and managed in conjunction with the
electric power architecture which sets the combustion cycle mass
air flow into the combustor 109, flame front progression and
thermal cooling of the combustor liner.
Stage 1--Initiate Combustion--Start
[0157] This stages is illustrated in FIG. 5A wherein the gas
turbine engine combustor 109 increases the enthalpy of the working
fluid by oxidization of fuel 502 and the subsequent dilution of the
resulting products with additional air until temperatures
acceptable to the turbine are achieved. From an operability
viewpoint, the combustor 109 must provide a flow environment that
is conducive to both ignition and the stability of the flame over a
wide variety of engine operating conditions. To meet steady
performance requirements, acceptable exit temperature profiles,
low-pressure losses and minimal pollutant emissions are necessary.
By-pass air dump regions 500 are located on opposite sides of the
turbine.
[0158] The start of AHMJET requires a ground based power supply to
electrify the electric ring motor compressor at the forward part of
the engine. The compressor, once running, compresses air for
combustion. In concept, air raised to 20 atmospheres will combust
in a highly atomized fuel mixture with the insurgence of igniters,
causing ignition at the flame holder in the annular combustor 109.
Numerically this is an air pressure of 292.4 PSI for initial
combustion, and 1000 degrees Fahrenheit . Temperature rise in the
combustor 109 with the spread of the flame front down the length of
the combustor 109 impinges the turbine blisk, rotating it, and this
starts generating electric power at the back end of the AHMJET from
the turbine ring motor generators. The combustion flame front 501
is viewable in the combustor region 109. Electric power from the
turbine ring motor generators (which is ahead of the MHD generator)
ramp up in power to sustain the electric compressor at the front
end of the engine and the power required to run the magnetic air
bearing of the electric compressor and the turbine generator. From
a stationary position through the start sequence, and until enough
power is generated by combustion to support the magnetic levitation
exoskeleton of the shaftless turbomachinary design, the mechanical
roller bearings embedded in the trunions of the compressor, and
turbine blisks allow the AHMJET to spin freely and come up to speed
whereby the exoskeleton is levitated by the magnetic bearings made
up of permanent magnets in the trunions and the induction coils in
the exoskeleton outer casing.
Stage 2--Idle Up
[0159] Idle up, as depicted in FIG. 6A, is the engine run sequence
where the AHMJET runs to high idle (estimated set point is 18,000
RPM) to operational temperatures and stabilized combustion and
energy generation conditions through the turbine magnetic
generator, and this power feeding electricity and sustaining
compressor operation for combustion without the ground power supply
for start-up. In idle up the MHD is non operational. Compression
ratios run a little higher as RPM is higher and at a higher
percentage of throttle setting. At start a 10:1 compression ratio
is typical, at idle up compression ratio runs to 12:1 with
operating temperatures between 1050 and 1200 degrees Fahrenheit
(estimated operating temperatures are 1600 degrees Fahrenheit).
Bypass air and compressor air are not at equal percentages, as more
compressed air is required for combustion and electric generation
while the system warms up and equilibrium is established between
compression and combustion, percentage ratios are 70% compression
air and 30% bypass air. Max thrust, dry/wet will vary with
compressor inlet temperature and pressure. Ionization ring 601 is
present in the combustor region. Feature 601 shows the by-pass air
inlet portion of the turbine, which is enlarged in detail in FIG.
6B.
[0160] FIG. 6B shows a bypass air gate 602 through which air flows
below a series of rotor 113 and stator 115 duets. Adjacent to the
air gate 107 are ring motor coils 603. Inverter 103 is depicted
herein to show the configuration of the bypass air gate 602
relative to the turbine.
Stage 3--Subsonic Combustion
[0161] In subsonic combustion and operation AHMJET acts as an
efficient low by-pass turbofan. This is depicted in FIG. 7A. Both
core compressor air and by-pass air contribute to combustion
processes. Flight regime is between 0.10 mach and 0.94 Mach with
by-pass air being routed through the by-pass gates which are open
between the compressor and diffuser stages, routing the air through
the exoskeleton wall in the exoskeleton casing channels, towards
the back of the engine, cooling the combustor 109 as it passes,
adding to the exhaust thrust and gas temperature, cooling as it
mixes with the hot turbine exhaust gases upon exit. Observation at
80% power, whereby exhaust nozzle 700 is open 80 percent, and a
subsequent 180 Lbs/Sec mass airflow 702 and above, and 1700 Degrees
F. exhaust gas temperature, and 20,800 gas horsepower, pushing
through an approximate 400 Sq/In conical nozzle. At ISO conditions
of 1000' altitude, 59 Degrees F. 37,000 to 38,000 Lbs thrust are
possible in subsonic cruise configuration.
[0162] The AHMJET engine in dual cycle (with downstream power
turbine running) is estimated at about 35% efficiency at subsonic
rated power. Therefore at 80% power 16,000 SHP (eight compressor
stage ring motors rated at 2500 SHP each is 20,000 SHP at 100%
power) is used to spin the rotor(s) 113 of the compressor 701
consuming 11.93 MW. The magnetic generation turbine aft of the
combustor 109, made up of four turbine blisks and magnetic
trunions, supplies 14.92 megawatts of power through the power
architecture of inverters 103 and buses 102. An additional load of
2980 SHP can be accommodated by altering the turbine nozzle throat
areas. Transonic operation includes turbine thrust air and by-pass
air for thrust with a front fan face mass air flow 702 above 180
lbs/Sec. By pass air ducts are open to feed bypass air past the
combustor 109 for cooling and to increase exhaust gas mixing and
thrust efficiency at exhaust exit 112. FIG. 7B depicts the proximal
portion of the hypersonic combustion ram 112 as the combustion gate
703 begins to move back.
Stage 4--Transonic Combustion
[0163] Transonic combustion is depicted in FIG. 8A and covers the
operation and flight regime typically between Mach 0.95 and Mach
1.2. It is the transition point for turbomachinary mechanics
whereby the engine cycle is demanded to change due to the change in
air velocity, subsequent mass air flow, temperature rise to higher
entropy state of supersonic combustion and increased air drag of
air through the combustor 109 due to eddy current destabilization
and subsequent parasitic drag. Transonic Combustion denotes the
largest change in heat transfer and the greatest change in "delta"
of entropy of the gas (both in heat dynamics and pressure) with the
AHMJET functioning as a pure turbine in this regime and transitions
electrically and magnetically from subsonic regime to supersonic
regimes. Initial combustion which pre-empts the start of the AHMJET
can be expressed mathematically and provides the basis and
uniqueness of the AHMJET combustion system and transition stages as
the amount of power form the system at this stage of combustion:
P=au2B2/1+B2.times.K(1-K)
[0164] Whereby combustion velocity is below 1000/meters per second
and combustion temperatures are below 1500 degrees Fahrenheit.
[0165] Individual steady flow performance models are typically
developed for each component in an engine design with results of
the performance of the combustor 109 and the turbomachinery are
predicted independently. The aerodynamic performance and durability
of the fan, compressor and turbine blading are predicted
independently of both one another and also independently of the
combustor 109, with the combustor performance predicted
independently of the upstream compressor. The surge and choke lines
bound the operating range of a gas turbine engine on a compressor
aerodynamic performance map. To assure compressor stability during
engine operation, an engine is designed with a surge margin. This
entails assuring that the operating point remains a specified
distance from the surge line on the performance map. Large surge
margins are employed due to transient conditions that move the
compressor operating point closer to the surge line.
[0166] However, a large surge margin that places the compressor
operating line far from the surge line can preclude operation at
the peak pressure rise or maximum efficiency region. Also, the
increase in operational range results in additional flexibility for
matching the compressor with the other gas turbine engine
components. The term surge line is actually a misnomer as two types
of instability can develop: surge or rotating stall. Surge is a
global axisymmetric oscillation of the flow through the compressor,
and can also include reverse flow during a portion of the surge
cycle.
[0167] These oscillations can result in severe damage to the
mechanical components of the engine from the unsteady thrust load
or the ingestion of combustion gases into the compressor and engine
inlet. In a severe surge cycle, the reversed flow through the
compressor can extinguish combustion, resulting in a "flame out" or
total loss of engine power. Rotating stall is a local flow deficit
that rotates around the compressor annulus. This flow deficit, or
cell, is a region in which the local mass flow is near zero.
[0168] The AHMJET technology is unique and novel in that each
compressor stage is operated separately as a thermodynamic and
compression device due to the shaftless exoskeleton design and no
drive shaft. Each independent compressor stage (a rotor 113 and a
stator) offers pressure differentials, as a Delta D, preventing
surge, particularly in front of the annulus of the combustor 109 in
the last compressor stage, as depicted in FIG. 7A. Separate
compressor stages offer separate RPM adjustments to surge pressures
when a pre-ignition or surge combustion occurs in the combustion
process when fuel atomization is in transition, particularly during
transonic conditions, again where enthalpy and entropy conditions
are not steady state. The central digital control computing system
of AHMJET can reduce or increase surge conditions to nullify or
reduce pressure differentials, even at high atmospheric conditions,
typically above 25:1 but below 30:1. This provides safety margin of
operation, reduction of flame out events and conservation of energy
and reduction of risk to implosion dynamics of rotating compressor
components and destruction of the combustor liners.
[0169] As illustrated in FIG. 8A, the exhaust nozzle 700 is 70
percent open. The gate of the magneto hyperdynamic drive 112 is
partially closed and the hypersonic combustion gate 802 moves back,
as depicted in 800. An enlargement of 800 is provided in FIG. 8A-1.
The exoskeleton bypass air gate is closed, as seen in highlighted
feature 801. FIG. 8B shows the distal end of the hydrodynamic
compression ram 111 as it begins to open.
Stage 5--Supersonic Combustion
[0170] Supersonic combustion occurs with both the electric
compressor and turbine generator in operation at compressor ratios
higher than 30:1, temperatures above 2500 degrees Fahrenheit, and
rotating speeds above 25,000 RPM. At this stage of operation there
is a surplus of electric power beyond what is required to run the
magnetically levitated electric compressor, drive the magnetically
driven compressor, from the gas turbine generator (four turbine
blisks generate power from the exoskeleton ring motor generators
and the embedded permanent magnets in the blisk trunions) and
sustain the magnetically levitated turbine rotor blisks with power.
This stage is illustrated in FIGS. 9A and 9B.
[0171] To attenuate the usage of propulsion in climb out and attain
efficient super cruise once at altitude of AHMJET in manned and
unmanned air vehicle applications, the turbine nozzle throat
changes geometry, hence exhaust velocity and pressure can be
modulated, so not only offering flight speed governance but also
offering an additional load of 4500 SHP available (3.35 MW) for
airframe electrical power (laser weapons and sensors) but
additional power to transition the AHMJET into transhypersonic
operation. Atmospheric pressure of the hot gas exhaust stream has
direct impact on the power density of the MHD drive generation
system. As the velocity of the hot exhaust gas increases due to
requirements of flight envelope to accomplish missions, power
density, or the amount of load that can be carried by the field of
magnetic induction from the hot jet exhaust gas stream of the
AHMJET.
[0172] Supersonic combustion in AHMJET covers the flight
operational envelope of the engine from Mach 1.2 to Mach 3.2. Above
Mach 3.2 the engine is considered to be in transhypersonic stage.
The operational limit of AHMJET in the supersonic regime is
constrained by material temperature limits of the combustor liner,
stationary and rotating turbine components. However, since AHMJET
is an exoskeleton inside-out design, these turbomachinary
components are loaded in compression and they can be manufactured
out of high temperature, fiber reinforced, hot isostatically
pressed (sintered) ceramic matrix composites. These sintered
materials exhibit significant higher temperature capabilities than
highly alloyed metals for these types of turbomachinary components
so that combustion processes in the supersonic regime where entropy
is the highest, they may withstand higher combustion temperatures,
thus higher operating temperatures and more complete combustion of
fossil fuels (Jet-A, Hydrogen, etc.). Mach 2.8 is near the limit of
combustion temperature, Mach number, exhaust velocity.
[0173] From seeding ports 104, there is selenium positive ion seed
flow 900 and negatively charged ions 901. The exhaust nozzle 700 is
50 percent open. The hypersonic magneto hydrodynamic drive cone 902
provides complete obstruction but is opened to the combustor 109.
FIG. 9B shows an enlargement of the opening of the cone in the
combustor region
Stage 6--Transhypersonic Combustion
[0174] Transhypersonic operation occurs above the 100% throttle
mark setting of AHMJET driven up by the transitioning of the MHD
drive coming on line in the engine and generating electric power.
Estimates are at 105% with therefore 21,000 SHP (eight compressor
stage ring motors 106 rated at 2500 SHP, producing 20,000 SHP at
100%) being required to spin the compressor rotor(s) 113. This
consumes 15.66 MW. Another element novel and unique about the
AHMJET technology is that in this combustion phase the magnetic
generation turbine aft of the combustor 109, made up of four
turbine blisks and magnetic trunions, plus the exoskeleton magnetic
plates 117 acting as anode and cathode supplies 14.92 megawatts
(MW) of power through the power architecture of inverters 103 and
power buses 102, with the difference of power requirements coming
from an additional load of 6600 SHP available (4.92 MW)
accommodated by alternating the turbine nozzle throat area. This is
in single cycle magnetic jet-electric generation just prior to the
MHD drive coming on line. The transhypersonic phase establishes
simultaneous combustion and generation cycles which are unique to
AHMJET, that allow the engine to transition from an air breathing
turbine cycle engine, to a pure air breathing scramjet combustion
hybrid.
[0175] Transhypersonic defines AHMJET as a propulsion machine as a
true hybrid in this stage as the majority of the
combustion/propulsion comes from the turbine generator and the MHD
drive has begun to come on line. Full operation of scramjet
propulsion occurs not until the exhaust magnetic flux passing
perpendicular to the MHD magnetic flux between the magnetic
conductive plates reach 5000 degrees Fahrenheit at which point the
energy density, or magnetic density is high enough to sustain the
continued magnetic levitation of the electric compressor and the
turbine generation, beyond which, in the final hypersonic stage,
the compressor and combustor 109 are shut down by the central
AHMJET computer 101 and the electric power architecture, and
combustion as a scramjet propulsor sustains flight speeds above
Mach 5.8 and generation capabilities above 15.75 MW, the minimum
amount of power required by the electric compressor to run and make
the transition from transhypersonic to hypersonic operation.
[0176] Transhypersonic combustion is depicted in FIG. 10A and 10B,
wherein FIG. 10 A depicts the air split 120 and opening of the
hypersonic combustion gate and pressure ratio. The intake air is
split between hypersonic combustion and compression combustion.
Petal cone 119 moves outward to direct air into the hypersonic
compression ram 111, which as previously described, is 100 percent
open. The compressor is partially closed. FIG. 10B illustrates the
distal portion of the hypersonic compression ram 111 in this
stage.
Stage 7--Hypersonic Combustion
[0177] While a ramjet is well suited for the cruise portion of the
flight, a ramjet can not generate static thrust. Another propulsion
system is needed to accelerate the aircraft until the ramjet can
generate sufficient thrust. This is the basis of the AHMJET of the
present invention in that it addresses the creation of combustion
and turbine technology for propulsion in the low speed ramjet
environment. Turbine Based Combined Cycle (TBCC) engines are and
approach, and AHMJET provides a solution to the low speed
combustion problem with transitioning turbine cycle technology, MHD
electric power generation and magnetic propulsion.
[0178] Because of the pressure losses associated with the terminal
shock of the inlet, a ramjet has very limited performance beyond
Mach 5. For aircraft speeds which are much greater than the speed
of sound, the aircraft is said to be hypersonic Typical speeds for
hypersonic aircraft are greater than 3000 mph and Mach number is
greater than five, (M>5.0 The chief characteristic of hypersonic
aerodynamics is that the temperature of the flow is so great that
the chemistry of the diatomic molecules of the air must be
considered. At low hypersonic speeds, the molecular bonds vibrate,
which changes the magnitude of the forces generated by the air on
the engine inlet and diffuser. At high hypersonic speeds, the
molecules break apart producing electrically charged plasma around
the diffuser, engine inlet, and at the annulus to the combustor.
Large variations in air density and pressure occur because of shock
wave, and expansions of shockwaves around the aircraft.
[0179] The propulsion equation for hypersonic establishes
equilibrium challenges thermodynamically and chemically as current
technology has established no solution to true Turbine Based
Combined Cycles. It is the transition from turbine based, air
breathing aerodynamics, to non-turbine based combustion cycles,
where hypersonic combustion dynamics due to extreme air compression
in the diffuser causes dramatic atmospheric rises to the point of
combustion with atomized fuel pressure and an equilibrium must be
reached in the transition. Scramjet based combustion cycles are
critical as combustion is dependent purely on the extreme
pressurization of incoming hypersonic air, and past engine designs
have not been able to address this issue.
[0180] The AHMJET technology breaks away from past approaches in
turbine engine thermodynamics in that it provides dual combustion
chambers and exhaust chambers parallel to one another (this is
unique and novel), that not only where both turbine based
combustion and hypersonic propulsion thermodynamics can occur, but
the engine configuration and hypersonic combustion ramps/petal
gates 108 and 119 can close off the deleterious effects of
aerodynamics drag of rotating turbine components once hypersonic
scramjet combustion begins to occur, and the combustion process and
MHD electric generation can happen concurrently. This is depicted
in FIG. 11A. The velocity and shock wave front cause combustion in
the hypersonic compression ram without compressor stages.
[0181] The dual hypersonic MHD drive chamber and the parallel
turbine generator/MHD drive generator allow for the finite
transition between the upper limits of supersonic operation (Mach
2.8) and the lower limits of hypersonic scramjet combustion (Mach
3.3). FIG. 11B illustrates the hypersonic phase depicted in FIG.
11B with enlargements of regions 1101 and 1102. Region 1101
contains the bypass air inlet gate, similar to that illustrated in
FIG. 6B. Herein, region 1101 shows a further enlargement of the
compressor stage of the rotor 113 and stator 115.
[0182] FIG. 12 presents and inverted depiction of the rotor 113 and
stator 115 in the compression phase. It shows the single stage of
the turbine rotor ring motor generator 1206. In the outer rotor
trunion 1205, a permanent magnet is embedded therein. Trunion
cooling channels 1207 are depicted for by-pass air in stator 115.
Stator 115 has a high speed section 1201 and low speed section 103.
The rotor 113 has a corresponding high speed section 1200 and a low
speed section 1202. Intermediate fixed inner casing structure 1204
is set between the rotor 113 and stator 115.
[0183] The AHMJET has a significant quantity of ceramic matrix
composites in it, roughly 40% by weight. The rotors 113 and stators
115 of the vanes are to be made from high temperature, hafnium
carbide fiber-reinforced, ceramic matrix composites. Hafnium
carbide is typically utilized in its discontinuous fiber
reinforcement form, although it is available in continuous fiber
threaded forms. All these fibers are very small in diameter, with
twist (turns per inch).
[0184] Turbomachinary components in dynamic rotating environments
in engines must be manufactured and reinforced with continuous
reinforced fiber, as in the ceramic high temperature fiber, hafnium
carbide. Currently technology, followed by turbomachinary
manufacturers who use CMCs in static (not moving) components uses
short (or chopped) ceramic reinforcement fiber.
[0185] To meet dynamic loads of rotating turbine components, plus
hollow construction for cooling, fibers must be continuous, and to
follow configurations of vanes, stators and compressor buckets,
acute angles are prevalent.
[0186] A new method must be devised to use continuous fiber
performs (near net shape composite reinforcements of which are
bonded in composite tooling with the ceramic matrix, usually high
temperature silica). One aspect of the present invention involves a
method for manufacture of its vanes, stators, compressor buckets
and turbine blisks with continuous fiber.
[0187] The method approaches untwisting the hafnium carbide fiber,
and in some cases the silicone carbide reinforcement fiber so that
there is no twist, prior to weaving the fiber into a net shape
perform. The untwisting reduces or removes the shear load on the
fiber from the twist and makes it less brittle. For 90 degree
corners and more acute angles the fiber may be broken once,
untwisted and jigged to the correct angle, then the single yarns of
the fiber interwoven with the perform in the tool, rewoven to a
continuous net shape fiber as part of the preform. This is a
tedious job, but it has been found to be the only way to provide
continuity of maintaining a continuous load path for the fiber
reinforced ceramic. This sounds so very simple someone must have
thought about it. Well, turbine engine manufacturers are focused on
metal components because they are only using these in turbines with
driveshafts and everything is loaded in extension, so they cannot
use ceramic composite rotating (rotors 113, vanes, blisks)
components . Put everything in compression like in the AHMJET
design, as an inside-out, shaftless turbomachinary design, and
ceramics can be used.
[0188] Tooling for these ceramic components are typically highly
alloyed aluminum tools. Stitching the perform after untwisting the
fiber is completed first, then the perform of the vane or stator is
laid into the tool with previously coated mold release in it, the
tool is closes and the silica carbide matrix (glue) is injected in
the ports of the tool.
[0189] Ceramic fiber reinforced composites need to be cured under
pressure and temperature, usually to 7-8 atmospheres and a minimum
of 1200 degrees Fahrenheit, from 48 to 72 hours. This would be the
typical approach for compressor and turbine components such as
vanes, stators 115, buckets and rotors 113.
[0190] Turbine blisks are large, dynamic, highly detailed
aerodynamic components. They are a fully integrated turbine wheel
with the turbine airfoils integrated as part of the turbine wheel.
The manufacture of the hollow-core, air cooled turbine rotor
airfoils is set forth as follows. Turbine rotor airfoils are
generally air cooled, and thus manufactured as hollow parts. These
are the components that are directly behind the exhaust combustor
stators 115 aft of the combustor 109 where the exhaust gases are of
the highest temperature, and the velocity is the highest of the
gas. Thus operating temperatures are the highest and airfoils are
exposed to the greatest loads and temperatures. They subsequently
must be cooled. In all known advanced jet engine designs these
components are cooled by compressor air coming off the compressor
during operation of the engine.
[0191] To provide more efficient cooling for these dynamic
components, a manufacturing method using these components and
exposing them to more dynamic active cooling is disclosed herein.
Operating temperatures of these components behind the combustor 109
typically exceed 3500 degrees Fahrenheit. To prevent melting they
are typically exposed to cooling air from the compressor which
flows through channels in the vane or stator 115.
[0192] The AHMJET of the present invention is designed to operate
at above 5000 degrees Fahrenheit in hypersonic combustion regimes.
The stators 115, vanes, rotors 113 and blisks to be manufactured
may use nano-carbon tubules for reinforcement strength and for
cooling during the transhypersonic regime where the components are
exposed to these very high temperatures. It is known in the art to
use carbon nano-tube technology has been around for some period of
time and in the manufacture of turbine stators and rotors 113 where
the temperatures are the highest in the AHMJET, these hollow
structures are aligned radially in the component. The AHMJET
turbine ring motor generators are superconducting and cooled with
liquid helium and/or nitrogen.
[0193] This nitrogen pool is used in the jet electric turbine of
the present invention to cool the stator and rotor components in
the turbine rotor ring motor generator, passing the liquid nitrogen
through the nano-tubules embedded in the ceramic turbine
components. Manufacture of these components requires consolidation
of the ceramic structure under pressure and temperature, while
avoiding collapse of the nano-tubules. The nano-tubule structures
are pressurized to 5.0 atmospheres, post lay in the tool, and after
a vacuum assist of the infusion of the silicone carbide matrix.
[0194] It will therefore be appreciated by those skilled in the art
that the jet-electric turbine of the present invention and the
associated method of manufacture represents a substantial
improvement over the prior art.
[0195] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character, it
being understood that only the preferred embodiment has been shown
and described and that all changes and modifications that come
within the spirit of the invention are desired to be protected.
* * * * *